Field of the Invention
The invention relates to a radar apparatus having a sidelobe blanking circuit, provided with a main channel comprising a directive antenna, having a main lobe and sidelobes, and a main receiver; an auxiliary channel comprising an auxiliary antenna, having a directivity substantially lower than the directivity of the directive antenna, and an auxiliary receiver; and comparison and switch means connected to the main receiver and the auxiliary receiver for passing signals for further processing when the signals appear stronger in the main channel than in the auxiliary channel.
A radar apparatus of this kind is known from the patent DE 30 28 225 C1. The known radar apparatus is based on the principle that the auxiliary antenna gain is greater than the directive antenna sidelobe gain. Sidelobe suppression is then obtained to a satisfactory extent, except for noise sources entering the directive antenna main lobe flanks. Particularly, if the radar apparatus is provided with a difference channel for determining the error angle between a direction of the main lobe and a direction of a target, a noise source entering this way constitutes a considerable drawback.